Bin He, professor of biomedical engineering at the University of Minnesota, in Minneapolis, is skeptical of the system. He says there are some universal challenges with such systems and specifically with the EEG caps, even in a lab environment. Typically, neuroscientists use a conductive gel to help the cap's sensors collect as much information as possible. And even with the gel, signals that represent thoughts are very weak, he says.

There are other electrical signals that are stronger, however, and Emotiv's system could be detecting such signals in order to move virtual objects, says Alan Gevins, executive director of the San Francisco Brain Research Institute and president of SAM Technology. For instance, the electrical potential produced at the scalp from eye movements and facial and scalp muscles are at least 15 times stronger than those produced by activity in the brain. It is possible that when a person concentrates on pushing, lifting, or turning a virtual object, his or her eyes, jaw, head, or tongue move in a characteristic way, Gevins says.

But the fact that there is still much work to be done in EEG research in general leads Gevins to be skeptical of new consumer products. "You need not only advances in sensor technology, but also in application-specific signal analysis and, most importantly, [in] understanding which brain signals relate to thinking," he says. "And once you have that in the lab, it needs to be refined and refined and then refined some more."

While there still may be work to be done, Emotiv is betting that its technology is good enough for prime time, and it plans to make the system available to the general public in 2008. The question of whether or not Emotiv's technology will be a successful commercial product remains to be answered. Using the power of concentration to move virtual objects may have a novelty factor, but it is a slow and an unnatural way to manipulate objects in many gaming scenarios. Also, in order for Emotiv's system to work, the sensors on the cap must maintain contact with the scalp, which means that head and body movements should be kept to a minimum. Taking it out in the real world, Gevins says, could be difficult. "It doesn't do anyone any good to bring something out of the lab prematurely," he says.